Method of making container closures



.May 7, 1940. H. SEBELL METHOD OF MAKING CONTAINER CLOSURES Fiied Sept. 16, use s Sheets-S haet 1 I I n n J I u i May '7, 1940.

, SEBELL METHOD OF MAKING CONTAINER CLOSURES 3 Sheets-Sheet 2 filed Sept-.16, 193s Hoary Jei. %1 1% WWW May 7, 1940. H. SEBELL METHOD OF MAKING CONTAINER CLOSURES 3 Sheets-Sheet 3 Fired Sept. 1 1936 ?atented it? 7, i940 OF MAKING CONTAINER CLOSURES Harry Sebell, Boston, Mass, assignor, by mesne assignments, to Crown Can Company, Philadelphia, Pa., a corporation of Pennsylvania Application September 16, 1936, Serial No. 101,153

MEOD

I 12 Claims.

The present invention relates to-methods of manufacturing container closures, and the principal object of the invention is to provide a container and a closure therefor of relatively simple and inexpensive construction which will form a tight'seal with the container and yet will permit a full pouring opening from the container when the closure is removed.

Another primary object of the invention is to provide a method of manufacturing container closures, including a method of applying and sealing such closures to a container.

Ancillary to the main objectives of the invention, it is my object to provide a closure of the plug type which is equipped with a sealing ring, which ring is expanded into intimate engagement with the container wall.

It is also an object of the present invention to provide a method whereby a preformed plug type closure may be initially sealed with the container wall in such manner that the closure may be removedand reapplied without diminishing the efiectiveness of the seal.

Another object of the invention is to provide several forms of plug type closures which may be manufactured and applied to a contained in accordance with the methods of the present invention.

The containers of the present invention are adapted for use in the packaging of various articles and materials, either dry or liquid, and with or without vacuum. Among the-dry articles which may be packaged in the containers of. the present invention are cigarettes, candy, mints and the like. However, the present invention will result in the greatest convenience, when employed in the packaging of such liquids as paints, whichare of considerable weight and necessitate a tight closure to prevent leakage from the containers.

Such liquids as paints have heretofore been packaged in containers such as metal cans which conventionally are made from a rectangular sheet of metal usually bent into cylindrical form,

the edges of the sheet being connected. by a con-' 'ventional lock or .lap type seam. In the use of paints and the like it is necessary to provide a closure which may be'removed and the contents partially taken iromthe can with a brush, after which it may be desirable to reapplythe closure with the expectancy of again removing the same when the remainder of the contents of the container is to be used. When a container such as a metal can with a longitudinal side seam is used in the packaging oi paints, it has been found to be extremely difficult to provide a removable closure which will form an efiectiveseal at the side seam of the can; it being evident that the conventional lock or lap type seam will distort the cylindrical contourof the interior of the mouth. of the can, making effective sealing dinicult. a

It has formerly been the practice in overcoming this difiiculty to equip the open end of the container with a seamless neck ring, said ring being formed from a single blank of material and usually being secured to the open end of the container by a double lock seam. When such a seamless neck ring is used, a closure of the plug type may be positioned therein to form an effective seal, the plug closure engaging the interior of the seamless neck ring without contact ing the end of the longitudinal side seam of the can.

While such containers have been successfully used, the cost of the container is materially increased by reason of the additional metal needed to form the seamless ring as well as the cost involved in forming and connecting the same with the container mouth.

To overcome the above mentioned difliculties without increasing the cost of manufacture, I have devised the container and methods of the present invention, which container employs a closure of the plug type having an annular groove in the outer wall of the skirt of the plug, which groove contains a sealing material of any appropriate composition adapted to intimately engage the wall of the container. the back oi the above mentioned groove is upset after the closure is inserted in the container mouth, so that the sealing material will be firmly pressed against the container wall.

Plug closures of the above type have heretofore been ineffective due to the difflculty of applying'the sealing material to the vertical skirt of the plug. Rings of rubber in solid condition The metal at applied to the groove of the skirt have not provedto be satisfactory, as they become unevenly worn and torn due to the movement of the ring within the groove when the closure is applied to and removed from the container during the no'rmal use of the l-atter; i

The sealing material whichI have found to be most emcient is any one of the well known compounds. applied in liquid form and permitted to solidify. A sealing compound when applied in this manner will 'efiectively fill the groove in which it is disposed and having solidified therein will be adhesively bound to the wall of the groove. The sealing compoundmay be of any appropriate composition, but a compound having a base of latex rubber has been found to be effective.

Heretofore, it has not been possible to apply a liquidsealing material to such closures as those of the plug type having a vertical wall or skirt with a groove therein for the sealing material because it was not possible to evenly distribute the material in the groove, as the same would flow from the groove, before it solidified sufiiciently to remain in position.

In order to overcome the above difliculties I have devised the closures and methods of the present invention in which the sealing material is applied to the closure before the same is completely formed, and when the closure blank is in substantially flat condition. The sealing material is permitted to solidify while the blank is in substantially fiat condition, after which the blank is finally formed for application to the container. I

Thedrawings, which are illustrative, and in no sense restrictive, disclose the manner in which the methods of the invention may be practiced and several types of containers which may be made in accordance with the methods. Apparatus is also disclosed which may be employed in practicing the methods, but it will be understood that different apparatus maybe designed to carry out the methods.

Figure 1 shows a blank of material such as one of metal from which the container closure is fabricated.

Figure 2 shows the blank after the same has been subjected to an initial step in the method, the blank still being in substantially fiat condition.

Figure 3 is an enlarged view of one side of the blank of Figure 2, after the sealing material has been applied thereto.

Figure 4 is a vertical sectional view through one type of apparatus and shows the manner in which a closure may be formed from the substantially fiat blank of Figure 3.

Figure 5 is a partial vertical sectional view through the closure, showing a subsequent step which places the closure in condition for application to the container.

Figure 6 is a vertical sectional view through a conventional container such as a metal can, showing the closure applied thereto.

Figure 7 is a partial enlarged view similar to Figure 6, showing an apparatus in position to seal the closure with the container.

Figure 8 is a partial vertical sectional view of the container and closure, showing the condition of the same after the sealing'operatlon of Figure 7 has been performed.

Figure 9 is a view similar to Figure 7,.showing another manner in which the closure may be sealed with the container.-

Figures 10, 11 and 12 show. modified forms of the container and closure which may be'made in accordance with the method of the present invention.

Referring to Figure 1, I. designates a fiat blank of appropriate material such as metal, from which the closure is to be fabricated. This blank may be of any desired configuration, but will usually be circular to conform with a cylindrical container. This blank is formed into the condition shown in Figure 2, in which figure the blank has a groove l2 depressed in the portion ll thereof which is to form the vertical ance of the succeeding operation of the method.

area or skirt of the closure. The groove l2 forms a closed path surrounding the center of the blank. The groove may be depressed in any desired manner, as by a stamping operation, and

will be circular and concentric with the blank 5 when the closure is to be applied to a cylindrical container. It will be noted that the back I! of the groove or depression I2 extends below the lower wall of the blank forming a protuberance, so that the metal of the groove may be operated upon in a manner hereinafter described.

Figure 2 also shows the formation of a cupshaped portion H in the blank which is to form the closure. This operation maybe conveniently performed at this stage of the method in order that the resulting closure will permit the containers to be stacked without becoming stuck to one another. However, the operation is not an important part of the method, and may be dispensed with if desired, and the blank of Figure 2 will be hereinafter-referred to as being in substantially flat condition in spite of the lilustration of the cup-shaped portion M in the blank.

The substantially fiat condition may include any condition of the blank in which the groove I2 is in such position that the liquid sealing ma-' terial may be applied thereto in an even manner and will not flow from the groove as would be the case were it attempted to apply the sealing material after the vertical area ll of the blank is bent therefrom into a skirt portion.

After the groove l2 has been formed in the blank, and while said blank is in the substantially fiat condition of Figure 2, a plastic sealing ma- 3 terial I5 is disposed in the groove. This seal-; ing material will preferably be flowed into the groove-I2 in liquid condition, and will be permitted to solidify therein before the perform If the sealing material is applied to the groove I2 in liquid condition, it will completely and evenly fill said groove and upon solidification will be adhesively bound with the inner walls of the groove. While the sealingmaterial is shown applied to the groove so that its upper surface is flush with the upper face of the blank l0, an additional amount of said material may be applied within the groove so that the material will protrude beyond the upper surface of the blank in order to provide a tighter seal when the closure is applied to the container.

While it is preferred that the sealing material be applied to the groove 12 in liquid condition, it-is possible that a solid or semi-plastic ring of the sealing material may be disposed in the groove l2 after which heat may be applied so that said material will assume substantially the configuration of the groove, and adhere thereto.

After the sealing material has solidified in the groove, the vertical area or skirt portion 'll of the blank is bent therefrom in the manner shown in Figure 4.- In this figure, a'suitable die apparatus is disclosed, comprising a lower female die 20 having an annular channel 2| therein, and an upper male die 22 having an annular male die member 24 for cooperation with the channel 2|. The upper die may be provided with a plate 25 adapted to rest upon the annular abutment 26 of the lower die member to retain the blank at point 28 where the vertical area II is bent from the blank. The plate 2.5 may be equipped with a circular projection 30 for cooperation with a circular depression 3| in the lower die 2' in 7 blank.

In performing the bending operation, the substantially fiat blank of Figure 2 will be positioned on the lower die 20 with the portion 28 thereof When the blank is thus positioned inthe lower die, the area. H thereof extends outwardly and horizontally over the opening of the annular channel 2! in the lower die,.and when the upper die is lowered, the annular male die member 2t thereof will engage the upper surface of the area ll of the blank, and bendthe same downwardly through substantially 90 to form the vertical skirt of the closure. The bend is made along a line between the center of the blank and the groove i2. During this operation, the male die member 25 willmove downwardly into the annular channel 2! forcing the area ll of the blank into said channel. The lower die may be equipped with any suitable cushioning means to assist in the bending operation, and as shown in Figure 4, an annular follower is positioned in* the channel 2i, said follower being mounted on a bolt 36 which is urged upwardly in channel 2! by a spring 31.

It will be observed that the diametrical dimension of'the channel M is slightly greater than depression E2 in said blank. Furthermore, it

will be'noted'that the outer wall of the die member 24 is in contact with the outer wall of the channel 2! during the bending operation so that.

a space39 is left between the inner wall of the male die member 24 and the inner wall of the channel 2!, this space being suiilcient so that the groove ii of the blank will not be distorted and the sealing material l5 will not be disturbed in its position in said groove during the bending operation. 4

After the vertical skirt II has been formed on the blank, an inwardly directed bead 40 may be rolled on the end of said skirt, as shown in Figure 5, this being done in any approved manner. The head is rolled in such fashion that a flat area 4| is formed at the outer termination of the skirt, which area. is adapted to engage the end of the container in a manner which will hereinafter be apparent. g

The closure preformed as discussedabove. is applied to the container in the manner illustrated in Figure 6 preliminary to the sealing of said closure with the. wall of the container. A container of conventional type in the form of a metal closure has been equipped with the groove l2 filled with the sealing material IS in the manner described above. 7 It will be noted that the metal can 42 has a order to fit the cup-shaped portion 54 of the.

full pouring opening, the flow of the contents therefrom being unimpeded by any devices such as conventional seamless neck rings which when applied, generally extend inwardly amaterial distance from the wall of the containertoward the 5 axis thereof. Furthermore, no pockets near the container mouth are formed when a container of the type illustrated is used, and no paint can be trapped with consequent wastage.

The closure is inserted into the container 39 mouth until the bead 40 of the closure engages the outwardly rolled bead '85 on the mouth of the container. When inserted, the open or front side of the annular groove I! .will face the inner wall of the container and the sealing material IS in 15 the groove will be in contact with the inner wall of the container. The exterior diameter of the skirt portion ii of the closure will preferably be of the same diameter or slightly greater than the internal diameter of the mouth of the container. 20

so that the closure will fit tightly therein. The

outer surface of the sealing material may be even with the outer surface of the skirt portionll of the closure, or it may protrude slightly beyond the surface of said skirt portion in order to more 25 container, it is desirable to form a seal which 9' will-absolutely preclude the possibility of leakage from the container during transportation by the loosening of the closure, such additional insurance against leakage being necessary in the packaging of paints and the like, which are of '35 high specific gravity. 7 I

In Figure 7 a device is illustrated which is useful in sealing the closure in the container mouth.

as for transportation purposes. This device comprises a plunger ill of such configuration that it 40 may move downwardly into the annular recess 48 in the outer wall of the closure, said plunger being of such dimension and being so positioned I that it will engage the back surface 53 of the channel 12 as at 49, and will upset the metal of 45 the back wall of the channel ahd-force the same toward the wall of'the container, resulting in the compression ofthe sealing material l5 within the channel against the wall of the container. The plunger 47 has connected therewith a plate 5! 50 ing a spring mounted on said-bolt between 55 plate 5| and follower 53. By'this construction, the follower 53 yieldingly engages the upper edge of the bead 40 of the closure and maintains the same in engagement with the bead 45 of the container. the applied closure to seal the same, the follower 53 will first engage the upper edge of the bead 40, and force the bead into engagement with the upper edge of the head 45, and during subsequent action of the plunger, the follower will yieldingly maintain the plug closure in position.

In Figure 8, the condition of the skirt ll-an groove 12 is disclosed after said groove has been upset by forcing its back'wall inwardly toward the wall of the container and'it will be observed that the rear wall of the groove is flattened out but that the adjacent walls of the skirt II have not'been distorted. It will be apparent that the sealing material will be firmly compressed against the wall of the container, so that there is no 5 When the-plunger 41 is moved toward 60 possibility of accidental removal of the closure.

When it is desired. to use the contents of the container, the plug may be initially removed by inserting a coin or other tool between the bead of the closure and bead of the container to,

pry the closure loose. The sealing material having been initially permitted to solidify in the groove l2 will not be pulled therefrom during the removal of the closure due to its adhesive engagement with the inner wall of the groove.

When the closure is removed, a complete pouring opening from the container will be provided. After the contents of the container have been partially usedfand it is desired to reapply the closure, the same may again be forced into position in the container, and the sealing material l5 will again form an effective sealing contact with the wall of the container. I A closure provided simply with a ring gasket of rubber in the annular groove in the skirt of the the insertion of the plug, it would undoubtedly be injured during the removal of the plug, particularly if the gasket had been pressed into intimate engagementwith the container wall in the manner disclosed above.

The disposition of the sealing material within the groove l2 protects the material from direct contact with the contents of the container be-. cause the groove is spaced from the inner end of the plug by the annularprojecting portion 59 of said plug. When the plug is reinserted after once having been removed, the portion 59 of the plug will scrape away any paint or the like along the wall of the container so that the sealing material will engage substantially bare metal.

It is preferred to initially seal the plug with the container wall in the manner described above. A similar result may be obtained, if, after the plug is inserted, the wall of the container is spun inwardly toward the open face of the groove 12 in the manner shown in Figure 9. -While any convenient type of tool may be utilized to perform this operation, Lhave shown a roll which is moved into engagement with the wall of the container in alignment with the groove l2, and pressure is applied against the wall of the container to annularly indent the same as at 6|. The indented portion of the container serves to com press the sealing material l5 within the groove so that accidental removal of the plug will be precluded. In this arrangement, the sealing material will preferably extend out beyond the engaging wall of the skirt l-l, so that it will not be necessary to force the metal of the indentation 6| of the container into the groove l2. That is, only suflicient indentation of the container wall to engage the protruding sealing material is necessary,

so that the closure may be removed after initial formed before application of the closure to the container, so that tool 60 need only indent the side wall sufficiently to compress the protruding packing l5, rather than indenting the skirt portion ll of the closure as well as the wall of the container, as would be the case were the groove I3 not preformed in the skirt. If desired, any type of backing chuck may be disposed in the annular channel 48 of the upper face of the plug during the indenting operation.

In Figure 10 another type of closure and container is disclosed which may be manufactured practicing the method of the present invention. The mouth of the container 42 in this modiflcation is provided with an inwardly turned bead 65, and the closure has an inwardly curved resilient skirt portion 66 terminating at its inner or lower edge in an outwardly turned head 61. Disposed in the annular depression on the outer wall of the skirt 66 above the bead 61 is a quantity of sealing material 66. The exterior diameter of the bead 61 of the closure is slightly greater than the internal diameter of the head of the container, and the skirt portion of the closure is of sufficient resiliency so that when the closure is forced into the open'mouth of the container, the bead 61 of the closure will spring past the bead 65 on the container wall, permitting bead 65 to firmly engage the sealing material 68 when the skirt expands. When the closure is snapped into place, the bead 61 will lock beneath the head 65.

The upper end of the skirt portion of the closure of the present embodiment is bent outwardly through substantially right angles and then back upon itself where it joins the upper face '10 of the closure, forming an annular projection II. The closure of this embodiment may be removed as hereinbefore described by inserting a coin or the like between the upper face of the bead 65 and the lower face of the annular projection H.

The sealing material 68 may be disposed in liquid condition on the closure of this embodiment, while the same is in blank form and in substantially flat condition, in a manner similar to that shown in connection with the embodiment of Figure 3. The blank may be in substantially flat condition, with an annular depression formed by the curved skirt portion 66 therein, and sealing material is-applied in this depression in substantially the same manner as shown in Figure 3. The sealing material will then be permitted, to solidify, after which the skirt portion 3 of the closure may be bent from the blank as hereinbefore disclosed.

Theouter diameter of the projection II is substantially the same as the outer diameter of the container in the present embodiment, this arrangement permitting conservation of space when the containers are transported stacked side by side. 1

In Figure 11 another container and closure is disclosed which, may be manufactured by practicing the method of the present invention. In this embodiment the mouth of the container 42 is provided with an inwardly pressed annular groove 15 in the wall of the container, said groove being spaced a short distance below said bead. The closure is equipp d with an inwardly turned bead 16 adapted to overlie the bead H in a manner and for a purpose hereinbefore described, and the skirt .portion of the closure is provided with an inwardly pressed annular recess 11 spaced from the inner wall I8 of the closure providing an annular shoulder "I9 0 the skirt below the recess 11. A sealing material 66 is and the inner face of bead M of the container, H

aieenae i 5 applied in the outer an of the skirt above the recess 1?, and in the corner where the skirt merges into the head It.

When this closure is forced into position in the container, the annular shoulder 19 on the closure will spring over the annular indentation. in the wall of the container so that the inner side of said indentation will enter the annular recess'l'l in the skirt portion oi the closure. Similarly to previous embodiments, the external diameter of the shoulder 19 is slightly greater than the internal diameter of the depression 15. The length of the skirt between the annular recess 11 and the lower faceof the bead it of the closure issuch that when the same is forced into position as shown in Figure 11, the gasket materiahw will be compressed between the wall 8| of the skirt and between the lower face of the head 16 of the closure and the bead it of the container.

Obviously the sealing material 80 may be applied to the closure blank of this embodiment when the same is in substantially flat condition,

and before the skirt of the closure is formed from the blank, in a manner similar to the method disclosed in connection with the embodiment of Figure 3. The sealing material is applied in liquid form to that portion of theclosure which forms the wall above the recess 'i'l, when the closure is in blank form and in substantially flat condition, after which the vertical skirt portion of the closure will be formed from the blank as described in connection with the embodiment of Figure 3. r

In the embodiment of Figure 12, the container is provided at its mouth with an inwardly turned head 85 identical with the bead $5 of Figure 10, and the closure has a resilient skirt portion 86 of slightly greater diameter than the internal diam.- eter of the head 85. The upper end of the skirt portion 86 terminates in an internal annular channel 81 which merges at 88 into an inwardly rolled bead 89 which is adapted to overlie the container bead B5. The sealing material 90 is disposed within the channelt'l in the outer wall of the skirt portion of the closure, and when) the closure is inserted, the skirt portion 86 will engage the bead 85 and will be compressed as said skirt portion moves by said bead, and the skirt portion will spring beneath the lower edge of the bead $5 sothat the latter will enter the annular channel 81 and compress the material 90 therein to secure a firm engagement of the closure with the container. In this embodiment, the closure may be removed by inserting a coin or the like between the beads 85 and 89 in a well .known manner.

It will also be noted that the external diameter of the head 88 of the closure is substantially equal to the external diameter of the container so that containers of this character may be stacked adjacent to one another with their side walls in contact with one another. Furthermore, the sealing material 90 of this embodiment may be applied to the blank from which the closure is formed while said blank is in substantially flat condition and'before the skirt portion is bent from the blank, in a manner similar to the method described in connection with the embodiment of Figure 3. -The sealing material isapplied to this closure in liquid condition when the same is substantially fiat, said material being flowed into the smaller channel 81 and permitted to solidify therein, after which the vertical skirt portion of the blank is formed.

Various modifications of the devices, methods and apparatus disclosed in this application may be made without departing from the scope of the invention. I claim:

1'. The method of manufacturing and applying to containers, a closure of the type having a vertical skirt adapted to engage in sealing contact with the wall of the container, which comprises providing a substantially flat closure blank, forming a depression in the blank in a portion thereof which is to form the skirt, said depression forming a closed path surrounding the center of the blank, disposing a plastic sealing material in said depression while the blank is in substantially flat and unformed condition, causing the material to solidify in said depression and adhere to the blank, bending the vertical skirt from the blank on a closed line between the center of the blank and said depression with said depression and sealing material in said area, applying the formed blank to the mouth of the container with the skirt in engagement with the wall of the container and the open side of said depression facing the container wall, and sealing the container by indenting the wall thereof opposite said depression toward the open side of said depression to force the sealing material therein into intimate engagement with the container wall.

2. The method of manufacturing a container closure of the type having a vertical area adapted to engage in sealing contact with the container, which comprises providing a closure blank having a substantially flat peripheral area, forming acup-shaped portion in the blank symmetrically disposed with respect to its center and within said peripheral area, and a depression in one face of said peripheral area spaced from and sur-- rounding the outer edge of said cup-shaped portion,,and thereby forming a corresponding pro- 3. The method of manufactur' g a container closure of the type having a cyli drical vertical area adapted to engage in sealing contact with the container, which comprises providing a circular closure blank having a substantially flat peripheral area, forming a cup-shaped portion in the center of theblank and a concentric annular depression in one face of said peripheral area spaced from the outer edge'ofv said cupshaped portion, and thereby forming a corresponding protuberance on the other face of said peripheral area, disposing a plastic sealing material in said depression while said peripheral area is substantially fiat and said blank in unformed condition, causing said materia to solidify in said depression and adhere to the lank, and then bending said peripheral area from the blank with said depression and sealing material-therein to form the cylindrical vertical area of. the closure, before applying the closure to the container.

4. The method of manufacturing a container closure of the plug type having'a vertical area adapted to engage in sealing contact with the infore applying the closure ,to the container.

peripheral area, forming a cup-shaped portion in the blank symmetrically disposed with respect to its center and within said peripheral area and a depression in one face of said peripheral area spaced fromand surrounding the outer edge of said cup-shaped portion, and thereby forming a corresponding protuberance on the other face of said peripheral area, disposing a plastic sealing material in said depression-while said peripheral area is substantially flat and said closure in 'unformed condition, causing the material to solidify in said depression and adhere to the blank, and then bending said peripheral area from the blank to form the vertical area of the closure with said depression and the solidified sealing material therein on the outer wall of the vertical area, before applying the closure to the container. I

5. The method of manufacturing a container closure of the type having a vertical area adapted to engage. in sealing contact with the container, which comprises providing a substantially fiat closure blank, forming a depression in one face of the blank in a portion thereof which is to form the vertical area and thereby forming a corresponding protuberance on the other face of the blank, said depression forming a closed path surrounding the center of the blank, disposing a plastic sealing material in said depression while 'the blank is in substantially flat and unformed condition, causing the material to solidify in said depression and adhere to the blank, and then bending the vertical area from the blank on a closed line between the center of the blank and said depression, with said depression and solidified sealing material in said area, before applying the closure to the container.

6. The method of manufacturing a container closure of the type having a cylindrical vertical area adapted .to engage in sealing contact with the container, which comprises providing a circular substantially flat closure blank, forming an annular depression in one face of said blank symmetrically disposed with respect to the center thereof in a portion of the blank which is to form the vertical area, and thereby forming a corresponding protuberance on the other face of the blank, said depression forming a closed path-surrounding the center of the blank, disposing a plastic sealing material in said depression while the blank is in substantially flat and unformed condition, causing said material to solidify in said depression and adhere to the blank, and then bending the cylindrical vertical area from the blank on a closed line between the center of the blank and'said depression, with the depression and solidified sealing material in said area, be-

7. The method of manufacturing a container closure of the plug type having a vertical area adapted to engage in sealing contact with the inner wall of the container, which comprises providing a substantially flat closure blank, forming a depression inone face of the 'blank in' a portion thereof which is to form the vertical area,

and thereby forming a correspondingprotuberance on the other face of the blank, said depressionforming a closed path surrounding the center of the blank, disposing a plastic sealing material in said;depression .while the blank is in 70. substantially flat and unformed condition',causing the material to solidify in said depression and adhere'tothe blank, then bending the vertical area. from the blank on a closed line hetween'the center of the blankand said depresslon. with said depression and the solidified sealing material on the outer wall of the vertical area, before applying the closure to the container.

8. The method of manufacturing a container closure of the plug type having a cylindrical vertical area adapted to engage in sealing contact with the inner cylindrical wall of the container, which comprises providing a circular substantially fiat closure blank, forming an annular depression in one face of the blank in a portion thereof which is to form the vertical area, and thereby forming a corresponding protuberance on the other face of the blank, said depression forming a closed path surrounding the center of the blank, disposing a plastic sealing material in said depression while the blank is in substantially flat and unformed condition, causing the material to solidify in said depression and adhere to the blank, and then bending the vertical area from the blank on a closed line between the center of the blank and said depression, with the de pression and solidified sealing material on the outer wall of the vertical area, before applying the closure to the container.

9. The method of manufacturing and applying to containers a closure of the type having a vertical skirt adapted to engage in sealing contact with the wall of the container, which comprises providing a substantially fiat closure blank, forming a depression'in one face of, said blank in a portion thereof which is to form the skirt and thereby forming a corresponding protuberance on the other face of the blank, said depression forming a closed path surrou'ndingthe center of the blank, disposing a plastic sealing material in said depression while said blank is insubstantially fiat and unformed condition, causing the material to solidify in said depression and adhere to the blank, forming the vertical skirt from the blank with the depression and solidified sealing material therein, applying the formed blank to the mouth of the container with the skirt in engagement with the wall of the container and the open side of said depression facing the container wall, and sealing the container by upsetting the metal of the skirt forming said protuberance to force the sealing material into intimate engagement with the container wall.

10. The method of manufacturing and applying to containers a closure of the type having a cylindrical vertical skirt adapted to engage in sealing contact with the cylindrical wall of the container, which comprises providing a circular substantially flat closure blank, forming an annular depression in one face of the blank symmetrically disposed with respect to the center thereof, inv a portion of the blank which is to form the skirt, and thereby forming a corresponding protuberance-on the other face of the blank, said depression forming a closed path surrounding thecenter of the blank, disposing a plastic sealing material in said depression while the blank is in substantially flat and unformed condition, causing the material to solidify in ing tocontainers a plug closure of the type having a'vertical skirt adapted to engage in sealing contact with the inner wall of the container, which comprisesproviding a substantially fiat closure blank, forming a depression in one face of said blank in a portion thereof which is to form the skirt, and thereby forming a corresponding protuberance on the other face of the blank, said depression forming a closed path surrounding the center of the blank, disposing a plastic sealing material in said depression while the blank is in substantially flat and un formed condition, causing said material to solid-- ify in said depression and adhere to the blank, bending the vertical skirt from the blank on a closed line between the center of the blank and ing to containers a plug closure of the type having a cylindrical vertical skirt adapted to engage in sealing contact with the inner cylindrical wall of the container, which comprises providing a circular substantially fiat closure blank, forming an annular depression in one face of the blank concentrically disposed with respect to the center thereof, in a portion of the blank which is to form the cylindrical skirt, and thereby forming a corresponding protuberance on the other face of the blank, said depression forming a closed path surrounding the center of the blank, disposing a plastic sealing material in said depression while the blank is in substantially flat and unioz'med condition, causing the material to solidify in said depression and adhere to the blank, bending the cylindrical vertical skirt from the blank on a closed line between the center ofthe blank and said depression, with said depression and the sealing material on the outer wall of the skirt, applying the formed blank to the mouth of the container with the skirt in engagement with the inner wall of the container and with the open side of said depression facing the container wall, and sealing the container by upsetting the metal of the-skirt forming said protuberance to force the sealing material outwardly into intimate engagement with the-container wall. I i 

